The RCWL-0513 is a mini, high-sensitivity microwave radar sensor module designed for human body motion induction. Operating on Doppler radar principles, it transmits a high-frequency electromagnetic wave and detects the changes in the reflected signal caused by a moving object. Unlike passive infrared (PIR) sensors that rely on heat signatures, this microwave module can detect movement through thin obstacles like plastics, glass, and wood, offering a full $180^\circ$ hemispherical detection zone.

Technical Specifications

• Operating Voltage: 4.0V to 28.0V DC
• Operating Current: Approx 2.8mA (Typical); 3mA (Maximum)
• Operating Frequency: Approx 3.2GHz
• Detection Distance: 5 to 10 meters (Adjustable via onboard components)
• Detection Angle: 180℃ (Hemispherical forward detection)
• Output Signal: High/Low Level (TTL: High 3.3V, Low 0V)
• Default Block Time: 2 seconds (Time after a trigger where new motion is ignored)
• Default Output Delay: 2 seconds (Length of time the OUT pin stays High after detection)
• Operating Temperature: -20℃ to +80℃

Features

• Penetrative Sensing: Penetrates non-metallic materials effortlessly. It can be hidden inside sealed plastic enclosures or behind drywalls to create completely invisible sensor setups.
• Ambient Light Regulation (Optional): Includes a dedicated pad for an optional photoresistor (LDR), allowing the module to inhibit motion triggering during daylight hours to save power in lighting systems.
• Wide Voltage Range: Features an internal low-dropout voltage regulator, making it compatible with both 5V and 12V – 24V industrial power networks.
• Onboard 3.3V Power Output: Provides a regulated 3.3V reference pin capable of delivering up to 100mA to power external microcontrollers or radio modules.

Pin Configuration

• VIN: Main power supply input (4V – 28V).
• GND: Common system ground.
• OUT: Digital output pin. Goes High (3.3V) when motion is detected, and drops back to Low (0V) when the detection window expires.
• 3V3: Regulated auxiliary power output (3.3V, Max 100mA).
• CDS: Light control disable pin. Connecting an LDR from here to GND disables the OUT pin during bright conditions.

Hardware Tuning Pads

The back of the PCB features optional SMD tuning pads that can be customized with discrete resistors or capacitors:

• C-TM (Output Time Adjust): Adding a capacitor here increases the output pulse width (extends the time the OUT pin stays High after motion stops).
• R-GN (Distance Adjust): Adding a resistor here reduces the sensing distance. A lower resistance value shortens the detection range from 10 meters down toward 5 meters.
• R-CDS (Light Threshold Adjust): Adding a resistor in parallel with an attached LDR changes the ambient light intensity threshold required to disable the module.

Common Applications

• Smart Home Automation: Automatically activating corridor or bathroom ceiling lights when a person enters.
• Intrusion Detection Systems: Invisible security alarms hidden behind wall panels or artwork.
• Interactive Commercial Displays: Activating digital signage or smart advertising kiosks when a consumer stands in front of the screen.
• Energy-Saving Appliances: Automated wake-up and sleep states for smart mirrors and terminal displays.

Usage & Installation Tips

• Metal Obstructions: Do not cover the front or back of the sensor with metal sheets or place it inside a metal container, as aluminum and steel shield the microwave radio waves and block motion detection.
• Component Clearance: Maintain a clearance of at least several centimeters from high-profile copper lines, electrolytic capacitors, or power transformers on adjacent boards to avoid parasitic interference.
• False Triggers: Microwave radar is highly sensitive and can detect moving water inside plastic pipes or wind-blown curtains. Calibrate the distance via the R-GN pad if false alarms occur in compact rooms.